Sibling Rivalry Frequent but not Foregone
![](https://media.wnyc.org/i/800/0/c/85/photologue/photos/tt/sibling.jpg)
Siblings between the ages of three and seven spend an average of ten minutes of every hour fighting, according to the book, "Nurture Shock"
( Flickr/Aislinn Ritchie (cc:by) )
( Flickr/Aislinn Ritchie (cc:by) )